Method of assembly of an electrical brush and terminal member

ABSTRACT

An electrical snap-in terminal and brush housing and method of assembly are disclosed. The terminal blade member is provided with a plurality of mutually opposed resilient tongues arranged to contactively abut wall means of the brush housing to retain, in a first or blade insertion direction, the terminal blade member within the brush housing. The terminal blade member is also provided with an enlarged shoulder portion to define the position of the terminal blade member within the brush housing in a second or brush insertion direction. In order to aid in the assembly of the brush means within the brush housing, the housing includes an open end portion having the dimensions of a substantial portion of the terminal blade member so that the terminal blade member may itself be used to compressively confine the brush biasing means and, once the biasing means are sufficiently compressed, the brush housing is provided with means to receive the terminal blade member within suitably provided structure comprising a slot and notches in the brush housing so that the terminal blade member will be removably secured within the housing.

United States Patent 1 [191 Apostoleris I 5] Nov. 19, 1974 [76]Inventor: Theodore G. Apostoleris, 3750 Miller Rd., Ann Arbor, Mich.48103 [22] Filed: Dec. 17, 1973 [21] Appl. No.: 425,642

Related US. Application Data [62] Division of Ser. No. 362,628, May 21,1973.

[52] US. Cl. 29/630 E, 29/628, 29/629, 29/630 R [51] Int. Cl H01! 9/00[58] Field of Search 29/628, 629, 630 R, 630 E;

339/176 MP, 255R, 258 R, 74 R, 256 R,

256 S, 276 T, 258 P; 310/239, 242, 245, 246,

FOREIGN PATENTS OR APPLICATIONS 1,958,192 6/1970 Germany 310/245 PrimaryExaminer-C. W. Lanham Assistant Examiner-James R. Duzan Attorney, Agent,or Firm-Robert A. Benziger; Keith L. Zerschling [57] ABSTRACT Anelectrical snap-in terminal and brush housing and method of assembly aredisclosed. The terminal blade member is provided with a plurality ofmutually opposed resilient tongues arranged to contactively abut wallmeans of the brush housing to retain, in a first or blade insertiondirection, the terminal blade member within the brush housing. Theterminal blade member is also provided with an enlarged shoulder portionto define the position of the terminal blade member within the brushhousing in a second or brush insertion direction. In order to aid in theassembly of the brush means within the brush housing, the housingincludes an open end portion having the dimensions of a substantialportion of the terminal blade member so that the terminal blade membermay itself be used to compressively confine the brush biasing means and,once the biasing means are sufficiently compressed, the brush housing isprovided with means to receive the terminal blade member within suitablyprovided structure comprising a slot and notches in the brush housing sothat the terminal blade member will be removably secured within thehousing.

6 Claims, 11 Drawing Figures METHOD OF ASSEMBLY OFAN ELECTRICAL BRUSHAND TERMINAL MEMBER This is a division of application Ser. No. 362,628,filed May 21, 1973.

BACKGROUND OF THE INVENTION brush means within a brush housing and whichis not orientation sensitive upon insertion into the brush housing.

2. Descriptionof the Prior Art The prior art, particularly asillustrated in my copending commonly assigned patent application Ser.No. 306,778 titled Dynamoelectric Machine End Plate And Mounting Means,and as reproduced in FIGS. 1, 2 and 3 of the instant patent application,illustrates a relatively simple, inexpensive and reliable terminal blademember construction and brush housing construction. The terminal blademember is comprised of a unitary stamping of suitable conductive metalsuch as, for example, copper or aluminum and is provided with a pair ofresilient tongue or finger elements which extend from the side of thetenninal blade member to provide an abutment engaging means forretaining the terminal blade member within the brush housing. The brushhousing is provided with a brush channel extending therethrough in onedirection and a terminal blade channel extending therethrough in asecond direction which is substantially perpendicular to the onedirection. The two channels are of substantially equal width.

This structure presents two major problems. Firstly, assembly of thebrush, brush biasing means and terminal blade member within the brushhousing is complicated. The brush and brush biasing means must beinserted within the brush channel. The brush biasing means must becompressed by the use of a blunt tool and while compressed, the terminalblade member must be inserted within the terminal blade channel. In theevent of improper alignment or premature withdrawal of the compressingtool, the terminal blade member will be improperly received within theterminal blade member channel. In the instance of those brush housingswhich are formed of a molded plastic, improper insertion of the terminalblade may also result in fracturing of portions of the housing. Theintegrity of these housing portions is relied upon to provide theabutment member for the resilient terminal blade fingers or tongues toretain the terminal blade within the housing. This problem has resultedin a significant number of field failures of dynamoelectric machinesusing this structure since the fractured housing may not be immediatelydetectable. I

The second problem, which is somewhat related to the first problem,resides in the fact that the unitary terminal blade member having theprojecting resilient fingers tends to be a one directional device. Thatis, the terminal blade member must be inserted within the terminal blademember channel of the brush housing with the resilient fingers directedaway from brush member so that the combination of forces from the brushbiasing means and the resilient fingers cause those tongues or fingersto engage the abutment means of the walls of the brush housing.Insertion with an opposite orientation will result in the brush biasingmeans urging the resilient fingers away from the abutment meansresulting in a loose or impositive terminal connection. This alsoresults in a significant number of field failures making the resultingstructure relatively expensive since field failure replacements involvereplacing the entire dynamoelectric machine. It is, therefore. an objectof the present invention to provide an improved terminal blade member.It is also an object of the present invention to provide an improvedbrush housing. It is a furtherobject of the present invention to providean improved method of assembly of the new terminal blade and the newbrush housing. It is a specific object of the present invention toprovide a unitary terminal blade member which may be inserted within theterminal blade member receiving channel or slots in any of the possiblepositions. It is also a specific object ofthe present invention toprovidev a terminal blade member which may itself replace thecompressing tool in the assembly stage thereby simplifying the assemblyprocess. It is also a specific object of the present invention toprovide an improved brush housing structure which may be of moldedplastic in which assembly forces and misalignment will not subject thehousing to fracturing and resultant field failures.

SUMMARY OF THE PRESENT INVENTION The present invention provides animproved terminal blade member which is of unitary structure. Theterminal blade member comprises a brush biasing wall portion for receiptwithin the brush housing and a conductor receiving portion having a pairof shoulders extending laterally to a greater extent than the brushbiasing wall portion. The brush biasing wall portion is provided withfront and rear wall elements each of which is provided with at least oneresilient finger or tongue member directed generally toward theconductor receiving portion and extending away from the terminal blademember. The conductor receiving portion of the terminal blade member isfurther provided with a pair of spacer elements which are directedgenerally perpendicular to the conductor receiving portion and locatedat the laterally extending shoulders.

The brush housing is provided with a brush channel and with a terminalblade channel. The brush channel is substantially open, or U-shaped,from the brush insertion end up to the terminal blade channel and is provided with a pair of cover wall means from the terminal blade channelinwardly to assist in confining the brush and brush biasing means. Theterminal blade channel is further provided with a pair of outwardlyfacing notches. The notches cooperate with the shoulders of theconductor receiving portion and with the spacer elements to define theposition of the terminal blade member within the housing in the brushinsertion direction while the finger elements of the terminal blademember and the cover wall portion cooperate to define the position ofthe tenninal blade member within the brush housing in the bladeinsertion direction. By pro viding a substantially open, or U-shaped,brush insertion region, the terminal blade member may be used as thecompressing tool and when the resilient means are sufficientlycompressed, the terminal blade member may be inserted so that its remoteend is within a slot provided therefor in the rear wall of the brushchannel and the shoulders and spacer elements are within the notchesprovided therefor in the housing.

The terminal blade member according to the present invention thus can beseen to cooperate with the brush housing of the present invention todefine an assembly in which the orientation of the terminal blade memberwith respect to the brush housing is bidirectional and which, followingassembly is relatively rigid in character. It will also be appreciatedthat, until the final terminal blade snap-in, the forces encountered inthe assembly process will be almost exclusively applied in the directionof the major axis of the brush channel thereby avoiding any applicationof forces of a character which could cause fracturing or splitting ofthe brush housing and the resulting field failures. By providing aterminal blade member having dimensions which substantially correspondto the dimensions of the receiving location provided therefor on thebrush housing, misalignment problems resulting in field failures arereadily avoided.

I By providing the terminal blade member with a first portion whichsubstantially corresponds in dimensions to the insertion region of thebrush channel, the termi- BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1illustrates, in a partial elevational view, a molded plastic brushhousing according to the prior art.

FIG. 2 illustrates, in an elevational view, a terminal blade member foruse with the brush housing of FIG.

FIG. 3 illustrates, in a sectional view, the terminal blade member ofFIG. 2 and the brush housing of FIG. 1 in assembled relationship.

FIGS. 4 and 5 illustrate, in an elevational view and in a perspectiveview, a terminal blade member according to thepre'sent invention.

FIG. 6 illustrates, in a partial elevational view, a

-molded plastic brush housing according to the present invention. FIG. 7illustrates, in asectional view, the termina blademember of FIGS. 4 and5 and the brush housing of FIG. 6 in assembled relationship.

FIGS. 8, 9, 10 and 11 illustrate, in perspective views the sequence ofsteps in the method of assembly of the terminal blade member of FIGS. 4and 5 in the brush housing of FIG. 6 according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings,FIG. 1 illustrates a partial elevational view of a dynamoelectricmachine end plate structure 10 according to my above-noted copendingpatent application Ser. No. 306,778. The end plate structure 10 isformed of a molded resinous or plastic material and is provided with anelectrical brush housing denoted generally at 12. The brush housing I2is comprised of a rear wall portion and a pair of upwardly extendingL-shaped wall members 14 which are arranged to be facing one another sothat the portions 16 which extend toward one another deiine cover wallmeans for a brush channel 18. A terminal blade channel 20 is formed byremoving a small section of each of the cover wall means I6 and byforming a matching slot or hole in the rear wall portion in alignmentwith the removed sections of the cover wall means. The channels I8 and20 extend generally perpendicularly to one another.

Referring now to FIG. 2, a terminal blade member 22 according to theprior art is illustrated. The terminal blade member 22 is formed of aunitary piece of su'it able metallic construction, such as for example.copper or aluminum and is arranged to be of substantially uniform widthfor insertion into the channel .20 of the brush housing 12 of FIG. I.The terminal blade member is provided with a conductor receiving portiondenoted generally as 24 having a first and a second conductor securingportions 26, 28 which extend generally perpendicularly away from theconductor receiving portion 24. Terminal blade member 22 is alsoprovided with a brush retaining portion denoted generally as 30.

A pair of resilient finger elements or tongues 32 are formed integralwith the retaining portion 30 and ex- .tend generally toward theconductor receiving portion 24. Tongues 32 are at a slight angle withrespect to the retaining portion 30 so that their free ends may extendlaterally away from the main portion of terminal blade member 22. Theterminal blade member 22 is provided with a width dimension whichsubstantially coincides with the width of the terminal blade receivingchannel 20 to provide uniform biasing of the electrical brushes asdescribed hereinbelow.

Referring now to FIG. 3, the terminal blade member 22 is shown receivedwithin the terminal blade channel 20 of the brush housing 12 in asectional view taken approximately along the middle of brush channel 18.The view also illustrates a brush member 34 and a brush biasing means 36received within brush channel 18. In preparing the assembly illustratedin FIG. 3, the brush 34 and brush biasing means 36 would be insertedwithin brush channel 18 from the insertion. or radially remote, end 38with the brush 34 being in abuting contact with a slip ring member, nowshown. Radial is intended to mean radial with respect to the axis ofrotation of the associated slip ring. The brush biasing means 36 wouldbe compressed through the use of a separate compressing tool to a depthsufficient to provide that the radially extreme end of biasing means 36was below, relative to FIG. 3, the tenninal blade channel 20. Terminalblade member 22 would be inserted within the opening of terminal bladechannel 20 and would be inserted part way within housing 12 so as toengage a major portion of the end of brush biasing means 36. The toolwould than be removed and the terminal blade member 22 would be insertedthe rest of the way through terminal blade channel 20. As shown 'in FIG.3, resilient finger member 32 'is arranged to abut wall portion 40 ofthe cover wall I6. Due to the biasing action of resilient means 36,terminal blade member 22 must be oriented with the finger elements 32extending away from the brush member 34. If the terminal blade member 22were inserted with the finger elements 32 directed toward brush member34, the reaction force of the brush biasing means 36 would preventfinger element 32 from engaging any abutment surface and the terminalblade member 32 would then rely solely upon frictional loading betweenthe terminal blade member 22 and the sidewall of terminal blade channel20 for retention of terminal member 22 within terminal blade channel 20.Furthermore, as discussed hereinabove, misalignment of terminal blademember 22 upon insertion into terminal blade channel 20 and- /orexcessive assembly forces could result in fracturing of the brushhousing channel particularly in the area of wall portion'40 of coverwall 16 so that the reaction force of brush biasing means 36 eventuallywould remove the material from this region and the brush would no longerbe biased toward its associated slip ring.

Referring now to FIGS. 4 and 5, the terminal blade member according tothe present invention and designated generally as 50 is shown in anelevational view, FIG. 4, and in a perspective view FIG. 5. Terminalblade member 50 is also comprised of a conductor receivingvportion 52and a brush retaining means 54. Conductor receiving portion 52 includesapair of elements 56, 58 which extend generally perpendicularly awayfrom the main portion of the conductor receiving portion 52 and areanalogous to the elements 26, 28 described hereinabove with reference toFIG. 2. Conductor receiving portion 52 is further provided with a pairof extending shoulders 60 which extend substantially beyond, in terms ofwidth, the brush retaining means 54. Shoulders 60 are further providedwith a pair of spacer elements 62 which are formed to extendsubstantially at right angles from shoulders 60 and whose function willbe more fully described hereinbelow.

Retaining means 54 is provided with a front wall portion 64 and a rearwall portion 66. The terms *front" and rear" are merely for purposes ofdifferentiation. The front and rear wall portions 64, 66 are formed bybending or folding a substantially planar terminal blade portion, as at68, through a substantially 180 bend to form the front and rear wallportions 64, 66 of retaining portion 54. Retaining portion 54 isprovided with a plurality of finger elements or tongues 70 with each ofthe front and rear wall portions 64, 66 being provided with preferablytwo each of finger elements 70. The finger elements 70 are substantiallyanalogous to the prior art finger elements 32 and are similarly situatedand formed.

Terminal blade member 50 retains the ease of fonnation of the prior artterminal blade member 20 (FIG. 2). Spacers 62 extending from theconductor receiving portion 52in the same general direction as theconductor retaining portions 56, 58 may be formed in the same formationprocess. Finger elements or tongues 70 may be formed in a fashionsimilar to the fonnation of the tongues 32 of the FIG. 2 terminal blademember. The terminal blade member 50 would-be provided with'the bend 68as a final formation step. This processcan be readily automated onexisting equipment by well known techniques.

Referring now to FIG. 6, the brush housing 72 according to the presentinvention is illustrated. As shown the brush housing is formed of amolded resinous or 'plastic material on an end plate member which issubstantially identical with that illustrated in FIG. 1. The brushhousing 72 has a back wall member, a pair of side wall members 74 and apair of cover wall members 76. The cover wall members 76 extend towardone another from the side walls 74 to define a pair of substantiallyL-shaped wall structures. A brush channel 77 is thereby formed. In orderto accomplish the specifics of the present invention, the cover wallmembers 76 do not extend radially to the brush insertion region 82.Further. side wall members 74 are provided with a pair of notches 78each of which have an inner edge 79 in alignment with the radially outeredge of the associated cover wall member 76. In order to provideadditional lateral support for the brush housing, each side wall 74 isprovided with a support wall 80 circumferentially located on the endplate member 10 in the vicinity of the notches 78. It can be seen byinspection. comparing the FIGS. 1 and 6, that whereas the side walls I4of the prior art brush housing were uninterrupted. the side walls 74 ofthe brush housing according to the present invention are notched as at78 to receive portions of the snap-in terminal blade member and inparticular the shoulders 60 and the spacing elements 62 ofthe terminalblade member 50 according to the present invention. Furthermore. tofacilitate assembly and avoid field failure problems, the cover wallmeans 76 do not extend radially beyond the inner edge 79 of notches 78whereas the prior art taught that the cover walls extend into the brushinsertion region 82 (where they are identified as 40 in FIG. .1).

Referring now to FIG. 7, the terminal blade member 50 is illustrated inassembled relationship within the brush housing 72. FIG. 7 is asectional view taken approximately along the radial center line of brushchannel 77 similarly to the FIG. 3 view. FIG. 7 also shows a brushmember 34 and a brush biasingmeans 36 received within brush housing 72and confined by terminal blade member 50. The portion of terminal blademember 50 in the vicinity of the fold 68 is received within a suitablyprovided slot or void 84 within the rear wall of brush housing 72comparable to that illustrated in FIG. 3 but having a substantiallylarger radial dimension. The resilient finger member 70 which is inproximity to the biasing means 36 is shown to be in abuting contact withthe cover wall means 76 while the finger element 70 which is more remotefrom the biasing means 36 is not in use. Shoulders 60 and spacerelements 62 of the terminal blade member according to FIGS. 4 and 5 arereceived within notches 78 to define in cooperation with the resilientfinger 70 in contact with the cover wall means 76 a relatively rigidremovably secured position for the terminal blade member 50 within brushhousing 76 which does not rely upon the resilient bias of the biasingmeans 36 or any frictional contact to maintain position.

By providing the terminal blade member 50 with the widened shoulder 60and the generally radially directed spacer elements 62 and by furtherproviding a brush housing 72 having notches 78 for receipt of theshoulders 60 and spacer elements 62 the present invention providesmaximum support (in the radial direction) for the terminal blade member50 while avoiding the exposure of relatively delicate cantilever plasticmaterial to any stresses which might tend to fracture that material.These elements cooperate to permit the radially generated forces(generated by brush biasing means 36) to be uniformly distributed overrelatively thick portions of the side walls 74. By arranging theresilient fingers 70 to engage the cover wall 76 radially inwardly fromthe terminal blade member 50, the fingers70 engage cantilever plasticstructure which is structurally stronger since it is of substantiallygreater length and is not subject to radially directed reaction forces.

Referring now to FIGS. 8, 9, and 11, the method of assembly of theterminal blade member 50 within the brush housing 72 is illustrated in asequence of perspective views which illustrate the various stepsinvolved. For convenience, the brush 34, brush biasing means 36 andelectrical connective wiring have been removed from the views in FIGS.8, 9 and 10 while a portion of the brush housing 72 has been broken awayin FIG. 11 to show the final assembly positioning. With the terminalblade member 50 removed from the brush housing 72, as shown in FIG. 8,brush 34 and brush biasing means 36 would be inserted within the brushhousing 72 through the entry portion 82 of brush channel 77 so that thebrush 34 is in electrical contact with its associated slip ring. Eitherwall 64, 66 of terminal blade member 50 would then be placed in contactwith the free end of brush biasing means 36 and the terminal blademember 50 would be moved in the radial direction to compress brushbiasing means 36 at least to the imaginary .plane established by inneredges 79 and notches '78. This would place the folded portion 68 ofterminal blade member 50 in substantial alignment with the slot or void84 provided therefor in endplate 10. When the brush biasing means 36have been sufficien tly comprssed, as illustrated by the relativeposition of terminal blade member 50 in FIG. 9, terminal blade member 50can then be moved to insert folded-portion 68 within the slot 84 in therear wall of the brush housing 72 while concomitently aligning shoulders60 and spacer elements 62 with the notches 78 as shown in Followinginsertion of folded portion 68 into the void' 84, .further insertionpressure will compress the resilient finger elements 70 which are on theside of the terminal blade member 50 in the direction of brush 34 sothat the terminal blade member 50 can be fully inserted. At fullinsertion shoulders 60 and spacer elements 62 will be received withinnotches 78 and the resilient fingers 70 will no longer be compressed andthe free ends of the finger elements 70 will move toward the brush 34 tothereby move behind cover wall means 76. Terminal blade member 50 willthereby become removably secured within the brush housing 72. FIG. 11illustrates the final assembled position relationship in a perspectiveview with a portion of brush housing 72 1 broken away. Conductor means86 in the conductor receiving portion 52 is included in this view.

It can be seen that the structure according'to the present inventionprovides a terminal blade member 50 which may be inserted within thebrush housing 72 in either of two directions making it positioninsensitive while further providing a structure which permits the use ofterminal blade member 50 as'the compressing tool for compressing theresilient brush biasing means inserting in a first direction the brushand biasing means within the housing;

compressing the biasing means with an end of the terminal blade memberto a degree sufficient compress all of the biasing means between thebrush and an imaginary plane defined by the terminal blade member finalposition;

sliding the terminal blade member generally perpendicular to the firstdirection until the end of the blade member enters a slot providedtherefor in said housing and the shoulders of said blade member arealigned with notches provided therefor in said housing; and

forcing said blade member end and said shoulders into said slot andnotches, respectively, until resilient fingers of said terminal blademember move freely behind wall means of said housing.

2. The method of claim 1 wherein the step of forcing said blade memberend and said shoulders is continued until widened shoulder portions abutthe bottom of the housing notches. I

3. The method of claim 1 wherein the step of sliding includes the stepof rotating the terminal blade member to a position substantiallyperpendicular to the first direction to further compress the brushbiasing means after the end of the terminal blade member has entered theslot.

4. The method of claim 1 wherein the terminal blade member has twosubstantially identical oppositely deposed brush biasing wall portionsand the step of compressing includes the step of orienting either of thebrush biasing wall portions to generally directed toward the brush.

5. A method of assemblying a resiliently biased electrical brush withina brush housing comprising the steps inserting the brush and brushbiasing means with a housing channel in a first direction; contactingthe free end of the brush biasing means with a brush biasing wallportion of a terminal blade member, the brush biasing wall portion beinggenerally perpendicular to the first direction; forcing the terminalblade member in the first direction'to apply a compressive force to thebrush biasing means; aligning the end portion of the terminal blademem-' ber witha slot provided therefor in a wall of the brush housingwhile aligning shoulder portions of the terminal blade member withnotches provided therefor in opposite walls of the brush housing; and

forcing the terminal blade member in a direction perpendicular to thefirst direction to cause the terminal blade member end portion andshoulder portions to enter the slot and notches, respectively.

6. The method of claim 5 wherein the step of forcing behind wall meansof the brush housing.

1. A method of assemblying a resiliently biased electrical brush within a brush housing comprising the steps of: inserting in a first direction the brush and biasing means within the housing; compressing the biasing means with an end of the terminal blade member to a degree sufficient compress all of the biasing means between the brush and an imaginary plane defined by the terminal blade member final position; sliding the terminal blade member generally perpendicular to the first direction until the end of the blade member enters a slot provided therefor in said housing and the shoulders of said blade member are aligned with notches provided therefor in said housing; and forcing said blade member end and said shoulders into said slot and notches, respectively, until resilient fingers of said terminal blade member move freely behind wall means of said housing.
 2. The method of claim 1 wherein the step of forcing said blade member end and said shoulders is continued until widened shoulder portions abut the bottom of the housing notches.
 3. The method of claim 1 wherein the step of sliding includes the step of rotating the terminal blade member to a position substantially perpendicular to the first direction to further compress the brush biasing means after the end of the terminal blade member has entered the slot.
 4. The method of claim 1 wherein the terminal blade member has two substantially identical oppositely deposed brush biasing wall portions and the step of compressing includes the step of orienting either of the brush biasing wall portions to generally directed toward the brush.
 5. A method of assemblying a resiliently biased electrical brush within a brush housing comprising the steps of: inserting the brush and brush biasing means with a housing channel in a first direction; contacting the free end of the brush biasing meaNs with a brush biasing wall portion of a terminal blade member, the brush biasing wall portion being generally perpendicular to the first direction; forcing the terminal blade member in the first direction to apply a compressive force to the brush biasing means; aligning the end portion of the terminal blade member with a slot provided therefor in a wall of the brush housing while aligning shoulder portions of the terminal blade member with notches provided therefor in opposite walls of the brush housing; and forcing the terminal blade member in a direction perpendicular to the first direction to cause the terminal blade member end portion and shoulder portions to enter the slot and notches, respectively.
 6. The method of claim 5 wherein the step of forcing includes the step of moving the terminal blade member in the direction perpendicular to the first direction until resilient fingers on said terminal blade member move behind wall means of the brush housing. 